Recruitment signals in juvenile cod surveys depend on thermal growth conditions

Coastal seine surveys contain some of the only direct measures of age-0 abundance for Atlantic cod Gadus morhua and Pacific cod G. macrocephalus, yet their utility in forecasting future year-class strength has not been evaluated among regions. We analyzed coastal time-series from the Gulf of Alaska, Newfoundland and Norway to test the hypothesis that recruitment signals are stronger when assessed under thermal conditions that provide high juvenile growth potential. Weaker recruitment signals were associated with low growth potential from cold winters (Newfoundland) and recent warmer summers (Norway). We conclude that temperature-dependent growth strongly influences the utility of coastal surveys in recruitment forecasting among regions. Temporal changes in growth potential (e.g., via climate change) will likely affect recruitment signals by way of changes in juvenile mortality or spatial shifts to more favorable thermal habitats.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author